Tag Archives: Invasive Species

One of our first posts at Frogs Are Green was about the coqui, a frog native to Puerto Rico, where it exists alongside several other species of Eleutherodactylus frogs and where a biological balance is maintained. It was introduced to Hawaii in the mid- to late 1990s and has no competitors so it has spread unchecked and is considered an invasive species. But our guest author, Sydney Ross Singer, a medical anthropologist, biologist, and author living on the Big Island of Hawaii, would like us to look at this problem from a new perspective. Perhaps this “alien” species should not be rejected and destroyed but welcomed.

Besides being beautiful, fascinating, a source of medicinal substances, and essential for healthy ecosystem function, frogs are canaries in the environmental coal mine. They are sensitive to pollution and climate change. And their numbers are declining at extinction rates.

That’s bad news for the rest of us living in the coal mine. Clearly, we need to change our ways.
But change is difficult for a culture to accept. Until people are dying at the rate of frogs, nothing will alter our bad cultural behaviors.

So the next best thing to do is try saving the frogs. We may not be able to stop pesticide and herbicide use, or end the deforestation and development of wild areas, or stop all the industries and lifestyles that contribute to climate change. But we can catch frogs where they are declining and find new, healthier places for them to live.

We might not have the political and economic clout to stop multinational corporations from exploiting and altering the world’s environments. But we can help refugee species flee the destruction and avoid extinction.

There are places on the planet that can serve as sanctuaries for these refugees. One place, in particular, stands out as one of the best – Hawaii.

If you move frogs from one place to another that already has frogs, the immigrants will compete with the natives, and you can possibly lose native frog populations. Hawaii, however, has no native frogs, or any native reptiles, amphibians, land snakes, or lizards. What better place to introduce frogs? Lots of insect pests to eat, warm and humid conditions, and few predators. If we wanted a sanctuary for endangered and threatened frogs, this is the place.

But wait. Can we just move a species from one part of the planet to another? Won’t it become invasive and cause damage?

It is this question that is keeping frogs from finding new homes. According to current trends in environmental thinking, species “belong” where they are “native.” You’re not supposed to move them to places where they “don’t belong.” When it comes to frogs, the Hawaii government has said they clearly “don’t belong.”

Of course, there are already frogs and toads in Hawaii, which were brought by environmental managers for insect control decades ago. Back then species were introduced deliberately to enhance biodiversity and provide needed environmental services, such as pest control, or to serve as a food source. The environment was seen as a garden for us to plant and inhabit as we saw fit.

That has all changed. Now the goal of managers is to kill introduced species in order to preserve and restore native ecosystems as they had existed prior to western contact centuries ago. They won’t get rid of the people, or the agriculture, or the chemical spraying, or the bulldozing, or the deforestation, or the development, or the intercontinental shipping, or the industries and energy policies that help cause climate change. It’s hard to change these aspects of the culture. But you sure can kill things that “don’t belong.”

What was called “exotic” or “immigrant” is now called “alien” or “invasive.” We have gone from an open immigration policy to a bio-xenophobia.

When coqui tree frogs accidentally arrived in Hawaii with shipments of plants from Florida or Puerto Rico, the response was ballistic. The mayor of Hawaii declared a state of emergency. Scientists feared the sky was falling, and that the coquis, which eat lots of insects, would decimate the insect population to the point of starving all other insectivorous creatures. The sound of the frogs, a two-toned “ko-KEE”, was described as a “shrill shriek” guaranteed to keep everyone awake at night, run down property values, and drive away tourists.

Ironically, this same coqui frog is the national animal of Puerto Rico, its native land. In fact, Puerto Ricans love this frog and its chirping sound so much that it is honored in local folklore. People describe the nighttime sound of the coqui as soothing and necessary for sleep, and Puerto Rican travelers often bring recordings of coquis with them when away from home to help them sleep.

Puerto Rico has numerous species of coqui frogs, many of which are now extinct or threatened. Unfortunately, frog numbers are declining because of fungal infections, development, climate change, and pesticide and herbicide use. So you can imagine how angry and upset Puerto Ricans were when Hawaii announced its Frog War to eradicate the newly arrived coquis.

Over the past 10 years, millions of dollars have been spent in Hawaii trying to kill coquis. And despite wide cost-saving cuts in government spending, there is still money to kill coquis.

At first, they tried an experiment to kill coquis with concentrated caffeine, giving the frogs a heart attack. A special emergency exemption was needed from the EPA to allow this spraying of caffeine into the environment. It’s impact on humans, pets, plants, lizards, and other non-target species was unknown, or what it would do once it entered the groundwater and flowed to the oceans. Chemical warfare suits were needed by applicators to prevent exposure to the highly dangerous caffeine, which was at concentrations 100 times that of coffee. There is no antidote for caffeine poisoning.

When the caffeine experiment proved untenable and too dangerous, citric acid was encouraged as a frogicide. Sprayers soaked the forests with acid, sometimes sprayed from helicopters, to drench the tiny frogs and burn them to death. Of course, this also killed plants and other critters, such as lizards. But since lizards are non-native, nobody in the government cared.

But citric acid is expensive. So another experiment was tried, using hydrated lime to burn the frogs. This caustic chemical can also cause irreversible eye and lung damage to people and pets on contact, so another emergency exemption was needed from the EPA to experiment with it. As it turned out, the hydrated lime didn’t work very well, and it killed lots of plants.

So the University of Hawaii experimented on developing a frog disease to unleash on the frogs. They tried a fungus to infect the frogs, the same one killing frogs elsewhere in the world. They realized the fungus might also kill the geckos, skinks, anoles, and other lizards, as well as the toads. But since none are native to Hawaii, none of the eradicators cared. In fact, destroying all the lizards and toads would be considered a plus. The coqui frogs, however, survived the fungus, so it was never released wide scale.

By now you may wonder how people can get away with this abuse of frogs. Aren’t there laws protecting animals from this type of cruelty?

There are. So to get around the laws the Hawaii legislature passed a law defining the coqui as a “pest.” Pest species are exempted from humane laws.

This moral depravity reached its zenith in 2007, with a planned Coqui Bounty Hunter contest to be held by public schools on the Big Island. Schools instructed students to kill coquis, either by burning them with acid, cooking them alive, or freezing them. The school with the most “kills” would receive a prize — the violent video games Playstation 3 and Xbox. The contest was canceled once it was pointed out to the schools that students are supposed to receive humane, not inhumane, education.

Despite the eradication attempts, the frogs spread. Actually, sometimes they spread because of these attempts, since coquis try leaving areas disturbed by spraying. An interisland quarantine on the coqui still exists, requiring all plant nurseries to treat plants with hot water, proven lethal to coquis and their eggs, prior to transport to other islands. But the coquis seem to frequently survive that, too.

So here is the irony. Frogs are disappearing from everywhere in the world except in Hawaii, where the government is trying to make them disappear.

Yet, despite the endless anti-coqui propaganda, people are coming to like the little coqui frog, especially those people who have arrived to Hawaii since the advent of the coqui. To these people, the sound of Hawaii includes the coqui. To these new human immigrants, the coqui is normal, and enjoyable. They understand why the Puerto Ricans love these frogs.

If we are to save the world’s endangered and threatened frogs, and other wildlife that needs rescue from the human-damaged world, we need to change our environmental immigration policy. It doesn’t matter where a species is native, or where it “belongs”. That these species survive is what matters. And this may require finding them a new home.

This is not to suggest that we bring in species willy nilly, without thinking about the impact on local species. We need careful study to know which species can be introduced, and where. But unless we open our borders, and our hearts, to these refugee species, they will die.

We caused their problems. Their fate is in our hands.

ABOUT THE AUTHOR:
Sydney Ross Singer is a medical anthropologist, biologist, and author living on the Big Island of Hawaii. He is an outspoken defender of the Hawaiian coqui frog, has created Hawaii’s first coqui frog sanctuary, and has been featured on Animal Planet, PBS Nature, BBC radio, and Univision. He is co-author of Panic in Paradise: Invasive Species, Hysteria, and the Hawaiian Coqui Frog War (ISCD Press, 2005). His website is www.HawaiianCoqui.org.

Super species are the phenomenally successful invasive creatures—animals, plants, and microbes—that are dominating ecosystems around the globe. Feral pigs are relentlessly trampling across Europe, North America, and Australia. Jellyfish are dominating the world’s oceans, clogging fishing nets. Not to mention the invasive species that are in our own backyards: house sparrows and eastern gray squirrels.

In Super Species: The Creatures That Will Dominate the Planet (Firefly Books, published October 2010) Garry Hamilton details the fascinating stories of the species that seem to have won the natural selection sweepstakes. Some of these super species include the European green crab, the giant African land snail, the Argentine ant, nutria, zebra mussels, the chytrid fungus, and killer algae.

One of the species he describes, the invasive American bullfrog, especially concerns us at Frogs Are Green. Hamilton contends that bullfrogs are more invasive than Australia’s notorious cane toads. The reasons are many—bullfrogs were shipped around the world for use as biological control agents, as pets, or for sport.

Frog farms have also led to their introduction to nonnative areas. In the late 1800s after gold miners out West ate their way through native frogs, entrepreneurs imported American bullfrogs from back East to satisfy the increasing demand. Eventually farming bullfrogs spread to other parts of the world as well.

As Hamilton describes it, bullfrog farming isn’t easy and many of the frogs in these “farms” were let loose. Most frogs wouldn’t have survived. But like many invasive species, bullfrogs are highly adaptable. Bullfrogs like deep, stable, non-moving aquatic habitats. This describes many human-modified environments: reservoirs, farm ponds, irrigation channels, and even garden water features.

Bullfrogs can survive through cold Ontario winters and the extreme heat of Southern U.S. summers. Female bullfrogs can produce between 6000 and 7000 eggs and as they mature, up to 25,000 eggs per clutch. As carnivorious amphibians, they prey on fish, water beetles, snails, turtles, bats, voles, ducklings, snakes, lizards, and salamanders.

Bullfrogs compete with and prey on native frogs. This is one of the contributing factors to the worldwide decline of amphibians. Bullfrogs may also be helping to spread the deadly chytrid fungus, which is devastating frog populations around the world.

Attempts to deal with invasive bullfrogs have been challenging. But scientists have found that their numbers are fewer in waterways that haven’t been altered by people. As Hamilton writes, “By changing the physical parameters of a freshwater wetland, humans also change the playing field for all life-forms in the ecosystem, and this results in a cascade of ecological readjustments.”

The answer, Hamilton contends, is not to use the old methods such as killing the frogs and draining ponds. Rather, he says that in order to save native frogs, we need to save their habitats. Altering habitats is conducive to an invasion of bullfrogs.

I had mixed feelings reading about invasive bullfrogs. I like coming across them in ponds in the woods of upstate New York (one of their original habitats), their eyes peering just above the water, as they croak a bass jug-a-rum sound. One of my favorite frog books, The Frog Book, written in 1906 by naturalist Mary Dickerson, describes the bullfrog:

If we go rowing on river, lake, pond or park lagoon, some moonlit night late in late June, we are certain to hear the deep-toned call of the Bullfrog many times. Coming as it does at unexpected intervals and from unexpected directions, it seems startlingly weird in the quiet of the night. For June nights are quiet. The insect orchestras are not in full swing and the frog choruses have disbanded.

During Dickerson’s time, bullfrogs were less common than other frogs. At that time, they had many natural predators to keep them in control: snakes, otters, hawks, owls, herons, and turtles, and frog farming was mainly in the future. But human intervention tipped the balance.

In Super Species, Hamilton documents the story of many species like bullfrogs in which human intervention and alterations of habitats led to an imbalance. But his tone isn’t hysterical. Some invasive species like the plant kudzu, he contends, don’t actually have much of an impact on local biodiversity despite alarmist news stories. These species may actually be creating a new biosphere from the “rubble of our own destruction.”

This review is part of Ecolibris’s Green Books Campaign. Today at 1:00 p.m. ET, 200 bloggers will take a stand to support books printed on recycled or FSC-certified paper by simultaneously publishing reviews of 200 such books. By turning a spotlight on books printed using environmentally-friendly paper, Ecolibris wants to raise the awareness of book buyers to this issue and to encourage them to take it into consideration when purchasing books.

This holiday season, some Alaskans found “live” ornaments on their Christmas trees—Pacific Chorus frogs that hitchhiked in the trees to Alaska.

Courtesy of the Alaska Department of Fish and Game

Unfortunately, these little stowaways were not warmly received by the Alaska Department of Fish and Game. They are considered invasive species as they might carry fungi and viruses that could harm native frog species.

I imagine these frogs would be happier if they were sent home. Pacific Chorus frogs are native to Pacific coastal areas from Baja California up to Washington State. According to Lang Elliott in The Frogs and Toads of North America, its familiar two-part call, rib-bit, is the one most associated with frogs because they have provided the background “music” for so many Hollywood movies and TV shows.

Here’s the call of the Pacific Chorus frog in its native habitat—far from Juneau.

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